In a large mixing bowl, combine 3 cups of all-purpose flour, 2 teaspoons of active dry yeast, 1 teaspoon of sugar, and 1 teaspoon of salt. Add 1 cup of warm water and 2 tablespoons of olive oil. Mix until a dough forms, then knead on a floured surface for about 5-7 minutes until smooth. Place the dough in a greased bowl, cover with a damp cloth, and let it rise in a warm spot for 1 hour until it doubles in size.

While the dough is rising, heat 2 tablespoons of olive oil in a skillet over medium-low heat. Add 2 sliced onions and cook gently for about 20-25 minutes, stirring occasionally, until caramelized and golden brown. Add 2 minced garlic cloves and 4 cups of fresh spinach, cooking until wilted. Stir in 2 tablespoons of nutritional yeast, salt, and pepper to taste, and remove from heat to cool slightly.

Once the dough has risen, punch it down and roll it out on a lightly floured surface into a rectangle, about ¼ inch thick. Spread the cooled caramelized onion and spinach filling evenly over the dough, leaving a slight border. Carefully roll the dough tightly from one end to form a log, then slice it into 10-12 equal pieces. Arrange the rolls in a greased 9x13 inch baking dish, cut side up, and allow them to rise for another 30 minutes.

Preheat your oven to 375°F (190°C). Once the rolls have risen, bake them in the preheated oven for 20-25 minutes until they are golden brown and puffed. Keep an eye on them to prevent over-browning.

After baking, let the rolls cool in the dish for about 10 minutes before serving. They can be enjoyed warm right away or stored in an airtight container for up to 4 days.